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2.3.5 Typical Program 1 Results
The actual voltage coefficient you obtain using the program will,
of course, depend on the resistor being tested . The typical voltage
coefficient obtained for a 10GW resistor (Keithley part number
R-319-10G) was about 8ppm/V (0 . 0 08%/V) .
2.3.6 Program 1 Description
At the start of the program, the instrument is reset to default con-
ditions, and the error queue and data storage buffers are cleared .
The following configuration is then applied before the data col-
lection begins:
•
Source V, DC mode
•
Local sense
•
100mA compliance, autorange measure
•
1NPLC line cycle integration
•
100V
v1src:
•
200V
v2src:
The instrument then sources v1src, checks the source for com-
pliance in the function named Check _ Comp(), and performs a
measurement of the current if compliance is false . The source then
applies v2src and performs a second current measurement .
The function Calc _ Val() then performs the calculation of the
voltage coefficient based on the programmed source values and
the measured current values as described in
Coefficient
Calculations .
The instrument output is then turned off and the function
Print _ Data() is run to print the data to the TSB window .
Figure 2-3. Test configuration for capacitor leakage test
Section 2 . 3 .2, Voltage
Output HI
Series 2600
System
I
SourceMeter
Channel A
V
Source V,
Measure I
Output LO
Note: If the compliance is true, the instrument will abort the pro-
gram and print a warning to the TSB window. Check the DUT
and cabling to make sure everything is connected correctly and
re-run the test.
2.4 Capacitor Leakage Test
One important parameter associated with capacitors is leakage
current . Once the leakage current is known, the insulation resist-
ance can be easily calculated . The amount of leakage current in
a capacitor depends both on the type of dielectric as well as the
applied voltage . With a test voltage of 100V, for example, ceramic
dielectric capacitors have typical leakage currents in the nanoamp
to picoamp range, while polystyrene and polyester dielectric
capacitors exhibit a much lower leakage current—typically in the
femtoamp (10
A) range
–15
2.4.1 Test Configuration
Figure 2-3 shows the test configuration for the capacitor leakage
test . The instrument sources the test voltage across the capacitor,
and it measures the resulting leakage current through the device .
The resistor, R, is included for current limiting, and it also helps
to reduce noise . A typical value for R is 1MW, although that value
can be decreased for larger capacitor values . Note, however, that
values less than 10kW are not recommended .
2.4.2 Leakage Resistance Calculations
Once the leakage current is known, the leakage resistance can
easily be calculated from the applied voltage and leakage current
value as follows:
R = V/I
I
LKG
Capacitor
C
Under
Test
Test
Fixture
R
Resistor R required to
limit current and
reduce noise.
Typical value: 1MΩ
Minimum value: 10kΩ
SeCTIon 2
Two-terminal Device Tests
2-3
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